1. Field of the Invention
The present invention relates to an information processing apparatus and, more particularly, to an information processing apparatus in an image processing system that includes an information processing apparatus as an extended control apparatus which is appended to an image processing apparatus to extend its functions and flexibility. In this case, the image processing apparatus has, e.g., a printer function, image input function, document filing function, document transmission/reception function, image conversion function, and the like.
2. Description of the Related Art
In recent years, most of printers, scanners, FAX apparatuses, or image processing apparatuses which have multi-functions of these apparatuses comprise a network communication function. Some of these image processing apparatuses having the network communication function comprise a data transfer function of sending image data to a PC, server, or the like connected via a network.
In such a data transfer function, host protocols such as an SMTP protocol used to transfer e-mail messages, an HTTP protocol that can implement i-FAX and file uploading, an FTP protocol used to output files, and the like are used. “HTTP” is short for Hyper Text Transfer Protocol, and “FTP” is short for File Transfer Protocol.
On the other hand, as a means for extending functions of an image processing apparatus, a so-called external controller apparatus is available. Such an external controller apparatus achieves various extended functions. For example, the external controller apparatus can extend a network function to convert data of a network (LAN) communication format used in a user environment into data suited to an I/F scheme of the image processing apparatus. Also, the external controller apparatus provides an extended storage function that spools communication data, and a load distribution function that takes over some processes to be executed by the image processing apparatus or a client apparatus.
As a connection mode between such an external controller apparatus and image processing apparatus, the network communication function of the image processing apparatus may be used upon connection. As the connection mode in this case, a dual-network mode in which the external controller apparatus is inserted between the image processing apparatus and a LAN, and works as a bridge between the image processing apparatus and LAN is known. Also, a single-network mode in which the image processing apparatus and the external controller apparatus are connected to the LAN is known.
Upon comparison between the single-network mode and dual-network mode, the dual-network mode does not consume the bandwidth of the LAN since an independent local network is formed between the external controller apparatus and image processing apparatus in this mode. The external controller apparatus and image processing apparatus exchange a large volume of image data. In the dual-network mode, the independent local network can use a transmission scheme of a broader bandwidth than the LAN in such case.
Furthermore, in the dual-network mode, the external controller apparatus and image processing apparatus behave as one network apparatus. On the other hand, in the single-network mode, the external controller apparatus and image processing apparatus independently consume logical resources such as network addresses and the like and physical resources such as a hub, ports, and the like. Therefore, the dual-network mode consumes fewer network resources in the LAN than the single-network mode.
Japanese Patent Laid-Open No. 2003-99230 discloses a method of providing additional functional capability by an information processing apparatus (to be referred to as an extended control apparatus hereinafter) connected to an image processing apparatus.
FIG. 16 is a diagram showing an example of a network environment using a conventional extended image processing system.
An extended image processing system 10 is configured by an image processing apparatus 100 and extended control apparatus 101. This system provides further extended functions to the image processing apparatus 100 which has a printer function, image input function, document filing function, document transmission/reception function, image conversion function, and the like. A network interface card (to be abbreviated as NIC hereinafter: not shown) of the image processing apparatus 100 and a NIC 20 of the extended control apparatus 101 are connected via a LAN 402. Note that the NIC 20 is also called a local NIC, and the LAN 402 is also called a local network. A NIC 21 of the extended control apparatus 101 is connected to an external LAN 400, and communicates with other network nodes via the external LAN 400. Note that the NIC 21 is also called an external NIC, and the external LAN 400 is also called an external network.
A client personal computer (to be referred to as a client PC hereinafter) 11 is a personal information processing apparatus, and is mainly set on the desktop of the user to execute various application programs. The client PC 11 is connected to the external LAN 400, and uses services provided by other network nodes or provides services to other network nodes via the external LAN 400.
A server computer 12 is a large-scale information processing apparatus, is connected to the external LAN 400, and provides services mainly to other network nodes via the external LAN 400. A printer 13 is a network-compatible peripheral device, is connected to the external LAN 400, and provides services of the image processing apparatus to other network nodes via the external LAN 400. A router 14 is a network node which connects neighboring networks, and connects a wide area network (WAN) 15 such as the Internet, virtual private network, and the like and the external LAN 400.
A case will be explained below using FIG. 16 wherein the extended control apparatus 101 that can provide a secure print application function is connected to the image processing apparatus 100 which has no secure print application function.
In the network environment, a print job which is generated at one site in the network can be printed at another site. In some cases, confidential information or information associated with secrecy in another aspect must be printed.
Upon transmitting such confidential information to a device, a method of transmitting a print job encrypted on the client PC 11 side to the device, and printing the print job decrypted on the device side is known. Also, a method of temporarily storing print information sent from the client PC 11 by the device, and printing that information when the user has been successfully authenticated using an IC card or the like on the device side is also known. In order to assure security protection against electronic eavesdropping of transmission, a print job may be generally encrypted by an encryption method using a secret key. Also, in order to permit to view hardcopy printouts without authentication or to electronically eavesdrop and view print jobs stored in a print queue, authentication using an IC card may be used.
However, when the image processing apparatus 100 is the conventional one which does not incorporate any decryption module corresponding to the encryption method for each client PC 11 or does not incorporate any decryption module or user authentication system, a secure print function cannot be used.
The extended control apparatus 101 is used as a means for extending the functions of the image processing apparatus 100. The extended control apparatus 101 incorporates a decryption module corresponding to the encryption method for each client PC 11, and provides the decryption module and user authentication system to the conventional image processing apparatus, thus allowing the image processing apparatus 100 to use the secure print function. A secure print application of the extended control apparatus 101 receives encrypted print data from the client PC 11 using an LPD protocol, and stores the received data in a storage device in the extended control apparatus 101. When the user has been authenticated using an IC card or the like, the secure print application transmits the stored print data to the image processing apparatus 100, thereby printing that data.
Note that the extended control apparatus 101 is transparent to the client PC 11, and the image processing apparatus 100 seems as if it were processing the secure print function.
FIG. 17 is a diagram showing another example of the network environment that uses the conventional extended image processing system. The system shown in FIG. 17 is the same as that shown in FIG. 16, except for functions of an extended control apparatus 102.
A case will be described below using FIG. 17 wherein the extended control apparatus 102 which can provide an e-mail print application function is connected to the image processing apparatus 100 which does not have any e-mail print application function.
In the network environment, a print job which is generated at one site in the network can be printed at another site. In some cases, the image processing apparatus 100 is connected to the external network via a firewall having a function of blocking external invasions and attacks and so forth, and access to the image processing apparatus 100 except for e-mail is inhibited. However, even when access other than e-mail is inhibited, printing must be done depending on circumstances.
Upon transmitting a print job to the image processing apparatus 100 connected via the firewall, the following methods are known. That is, the client PC 11 side attaches the print job to an e-mail message, and transmits that e-mail message to the image processing apparatus 100. Then, the image processing apparatus 100 side prints the print job attached to the received e-mail message, or picks up the e-mail message including print information sent from the client PC 11 from a POP server, and prints the print information.
However, when the image processing apparatus 100 is the conventional one which does not incorporate any SMTP server function or POP client function, an e-mail print function cannot be used.
However, the extended control apparatus 102 is used as a means for extending the functions of the image processing apparatus 100. Since the extended control apparatus 102 incorporates the SMTP server function and provides the POP client function to the conventional image processing apparatus, the image processing apparatus 100 can use the e-mail print function. The e-mail print application of the extended control apparatus 102 receives an e-mail message including print information transmitted from the client PC 11, and transmits the print information to the image processing apparatus 100, thus printing the print information.
Note that the extended control apparatus 102 is transparent to the client PC 11, and the image processing apparatus 100 seems as if it were processing the e-mail print function.
According to the method disclosed in Japanese Patent Laid-Open No. 2003-99230, the IP address of the external NIC of the extended control apparatus uses that of the image processing apparatus, and that of the local NIC is assigned an IP address, which is registered in advance.
The destination address of print data from the client PC is that of the external NIC of the extended control apparatus. A communication is made so that the destination address of the print data from the extended control apparatus to the image processing apparatus is that of the NIC of the image processing apparatus, and the source address is that of the local NIC of the extended control apparatus.
However, the technique disclosed in Japanese Patent Laid-Open No. 2003-99230 poses the following problem upon daisy-chain connecting a plurality of extended control apparatuses between the LAN and image processing apparatus. That is, since the technique disclosed in Japanese Patent Laid-Open No. 2003-99230 does not take a combination of functions provided by the respective extended control apparatuses into consideration, the same IP address may be assigned to the local NICs of the respective extended control apparatuses. For this reason, this poses a problem for communications between application modules on the respective extended control apparatuses and those on the image processing apparatus.
Such a problem is not specific to the image processing apparatus and extended control apparatus, but is common in daisy-chains connecting the image processing apparatus and a plurality of information processing apparatuses via a local network.